Method of feeding sheets



J. E. SOCKE METHOD OF FEEDING SHEETS Filed June 19, 1957 May 3, 19Go United States Patent O METHOD F FEEDING SHEETS John E. Socke, Pelham Manor, N.Y., assignor to american Can Company, New York, N. a corporation of New Jersey Application June 19, 1957, Serial No. 666,669

`3 Claims. (Cl. 271-1) The present invention relates to a method of feeding sheets from a stack for a subsequent operation to be performed on them individually and has particular reference to feeding sheets which have scrolled edges.

In the manufacture of cans or containers, especially sheet metal cans' or containers, certain parts, such as the end or closure members, are cut from rectangular sheets of a size which permits of laying out the potential cutouts in the well known staggered relation which provides for economy of material. Where the can ends are to carry a protective coating, the sheets usually are fed from a stacked formation, through a coating machine prior to the cutting of the ends from the sheets.

In recent years, considerable experimentation has taken place in the cutting of can ends in staggered layout relation, from coil stock, i.e. a substantially continuous strip of material. In one method, the coil is rst cut into sheets, which sheets are stacked and then refed into the coating machine. In such a method, the severing of the sheets from the coil preferably is effected to produce an undulated or scrolled line of severance to provide for the desired stagger layout of the potential can ends. The resulting sheets thus have two oppositely disposed scrolled edges and two oppositely disposed straight edges.

In order to properly effect the feeding of such scroll edged sheets into the coating machine it is desirable to feed the sheets with a straight edge leading. This feeding operation usually is effected by a machine commonly known as a Dexter Feeder such as disclosed in United States Patent 2,221,981 issued November 19, 1940, to G. A. Martin on Sheet Feeder.

In such a machine pairs of suction cups lift the uppermost sheet in a stack to separate it from the next lower sheet in the stack and then while the rear cups let go, the leading cups advance the sheet longitudinally into the feeding rolls of the coating machine. It has been found however, that `as the lifted sheet advances from the stack with a straight edge leading, the scrolled edges of the top sheet and the sheet next below, interlock, and thereby cause the sheet next below to advance with the top sheet, with the result that each sheet in the upper portion of the stack interlocks with the immediate next below sheet so that several sheets move forward in chain reaction and cause a jam which often damages them beyond use. It is believed that burrs on the cut edges of the sheets are partly responsible for this interlocking action.

It is an object of the instant invention to overcome this difficulty by the provision of a method of feeding such scroll edged sheets wherein at least the leading scrolled edges of one sheet are shifted out of register with the scrolled edges of the subjacent sheet during the feeding operation so as to separate and free the scrolled edges of such sheets and thereby elect a proper consecutive feeding of the sheets without objectionable interlocking of their scrolled edges.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the Patented May 3, 1960 following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

Referring to the drawings:

Figure l is a schematic plan view of a scroll edged sheet to be fed from a stack in accordance with the steps of the instant method invention, the view illustrating in dotted lines the usual staggered layout of the potential cutouts;

Fig. 2 is a perspective view of a stack of sheets such as shown in Fig. l, the view illustrating a step of lifting the leading edge of the top sheet preparatory to feeding from the stack;

Fig. 3 is a schematic plan view of the stack shown in Fig. 2 with the leading edge of the top sheet of the stack in a displaced position to free the scrolled edges of the sheet relative to the next subjacent below sheet as an incident in the feeding of the top sheet from the stack; and

Fig. 4 is a view similar to Fig. 3, with portions broken away, the view illustrating the usual form of the scrolled edges of the sheets and a different manner of freeing the edges as an incident in the sheet feeding operation.

As a preferred and exemplary embodiment of the instant invention, the drawing illustrates a method of feeding scroll edged, generally rectangular, metal sheets 11 (Figs. l and 2) from a stack 12 of such sheets for the purpose of performing a subsequent operation upon the sheets individually. The sheets 11 are of the type usually severed from a substantially continuous web or strip of material, such as coil stock and as such have two oppositely disposed straight edges 14, 15 and two oppositely disposed undulated or scroll edges 16, 17. The particular shape of the undulations in the scrolled edges 16, 17 is immaterial. Figs. l, 2 and 3 illustrate square cut undulations for the purpose of explanation. However, the trapezoidal shaped undulations shown in Fig. 4 are usually preferred since they better accommodate the usual stagger layout of potential can ends 18 as shown in Fig. l in dotted lines for the purposes of illustration. It should be noted in Fig. 2 that in a stack of such sheets 11, the outer edges of the sheets, including the scrolled edges, are unavoidably in vertical alignment or register.

In order to feed the top sheet 11 from the stack without interlocking the scrolled edges 16, 17 with the identical scrolled edges 16, 17 of the sheet next below in the stack, the instant method invention provides for the displacement of at least the leading scrolled edges 16, 17 of the top sheet to be fed, relative to the corresponding edges of the next below sheet, as shown in Figs. 3 and 4. This preferably is effected by pushing the top sheet 1I, transversely of the stack, as by pushers 21 as in Fig. 3, to displace the scrolled edges 16, 17 of the top sheet laterally from the identical scrolled edges of the subjacent or next below sheet as shown in Fig. 3.

The lateral displacement of the top sheet '11 relative to its next below sheet may be effected while the sheet lies at against the next below sheet, but preferably the top sheet or at least its leading straight edge 14 is rst lifted free of the under sheet to insure complete separation therefrom. With the leading edge of the top sheet lifted, the sheet then as a whole, preferably is laterally displaced as shown in Fig. 3. The lifting of the top sheet preferably and usually is effected by vacuum or suction cups 23. These vacuum cups 23 thereafter advance the lifted sheet from the stack 1'2 into the subsequent operation machine. With the scrolled edges 16, 17 displaced, the sheet is free to move forward, away from and along the top of the stack without interlocking of the scrolled edges.

As shown in Fig. 4, this same free feeding of the sheet may be effected by a diagonal displacing movement in the direction of the arrow, by use of a diagonally movable pusher 25, which movement may be combined if desired with the feeding movement of the vacuum cupsv 23. Y

Y It is thought that the invention and many of its attendant advantages will be understoodY from the'foregoing description, Vand it will be apparent that various changes may be made in the steps of the Vmethod described vand their order of accomplishment Without departing from the spirit and scope'f the invention or sacrificing 4all of its materia-l advantages', the method here` inbefore described being merely a preferred embodiment thereof.

I claim: Y l. The method of feeding rigid metallic sheets having scroll side edges from a stack of such sheets to avoid interlocking their scrolled edges, comprising the steps of lifting the leading edge of theruppermost sheet clear lof the next adjacent sheet in the stack to clear saidY leading' sheet edge from said next adjacent sheet andl to'sepa-V `rate the scrolled edges of said sheets, applying pressure to a scrolled edge of said uppermost sheet to shift the scrolled edges thereof laterally out of registry With the (age lifting the leading edge of the uppermost sheet clear of Vthe-next adjacent sheet in the stack to separate the scrolled edges thereof, applying horizontal pressure to a scrolled edge of said uppermost sheet to shift the same in one direction laterally of its scrolled edges to displace and offset said edges relative to the scrolled edges of said neitadjacent sheet Vin'vrt'he stack, and feeding said uppermost shifted/sheet in another angularly disposed direction to move said uppermost shifted sheet away from said stack. i n Y f t Y l L Jl V5. The method vof Vfeeding rigidv metallic sheetshaving scroll side edges from a stack of such sheets to preventY sticking of the sheets caused by interlocking their scrolled scrolled edges of said next adjacent sheet'i'n thestack, v

the uppermost sheet clear of the subjacent sheet in the stack to separate the scrolled'edges of such sheets, applying horizontal pressure to a scrolled edge of'said lifted sheet to shift the same `transversely and dispose its said scrolled edge at an angle rto the corresponding scrolled edge of said subjacent sheet, and feeding said;

lifted uppermost sheet away from said stack while trail'- ing its rear edge on said subjacent sheet.

References Cited in theV file of this patent 

